某微型商用车发动机进气系统设计开发

Design and Optimization for Intake System of Minivan Engine

为匹配某微型商用车,对某型发动机的进气系统进行了优化设计开发,开发对象为进气歧管与缸盖进气道。根据总布置条件确定了歧管气道的长度,通过CFD分析确定了歧管的最终优化方案。设计了一个增强进气滚流的进气道,稳态分析确认其流量系数基本持平,滚流比大幅提升。进气系统的瞬态分析表明,新状态进气系统在1000~4000r/min能明显增加进气量,进气道能够有效组织进气滚流,大幅增加压缩末期缸内湍动能水平,有利于改进燃烧过程。对根据新设计的进气系统制作的样机进行了台架试验,结果表明发动机在1000~4000r/min扭矩提升明显,中低转速下油耗率也显著降低,额定功率降低3kW,符合整车设计要求。

Intake system of some engine is chosen for new design to match a minivan, and the scope includes intake manifold and intake port of cylinder head. The length of runner of the intake manifold is figured out with consideration of package, and CFD analysis comes up with optimized detail concrete design of the manifold. A new intake port is designed with high tumble feature and is confirmed by CFD steady analysis. Dynamics analysis for the whole intake system indicates increase of intake air mass during 1 000~4 000 r/min conditions, desirable tumble organization and TKE distribution near top dead corner given by new intake port. Prototype engine with new intake system is put into dyno test and the result shows that the torque increases remarkably during 1 000~4 000 r/min, fuel consumption decreases also during mid low speed condition, rated power drops 3 kW, which meets the minivan design guide line.